Transit mixer revolution counter



Maid! 1960 R. E. SWARTHOUT 2,927,731

TRANSIT MIXER REVOLUTION COUNTER Filed Dec. 20, 1954 INVENTOR. R4 55545E 5W4R7H0l/7 ATTORNEY Unitcd States Patent TRANSIT MIXER REVOLUTIONCOUNTER Rassele E. Swarthout, Santa Monica, Calif., assignor toChallenge Manufacturing Co'., Los Angeles, Calif., a corporation ofCalifornia Application December 20, 1954, Serial No. 476,377

3 Claims-1C1. 235-91) This invention relates to counting and recordingthe revolutions and speed of revolutions of the drum-of a truck type. ortransit concrete mixer. Transit mixers are used to transport concrete"already mixed, as a mixer en transit to a point of use, or as a mixerat the point of use. Whether used in one way or another, the operationwill be benefited by counting the number and speed of revolutions of thedrums of such transit mixers, to give uniformity of quality of the endproduct and also remove guesswork from the operation. Thus, errors ofjudgment are, in a large measure, obviated and operator inexperienceremoved from affecting the quality of mix. The foregoing is particularlytrue where the mix must be performed according to specification requirements and affords an inspector or supervisor a sure and dependablemeans to ascertain that such requirements are being honored.

Since over-mixing of concrete as Well as under-mixing is not desirable,homogeneity of mix being lacking under both such faulty operations, itis an object of the present invention to provide novel and improvedmeans for readily determining the number and the speed of therevolutions of the drum of a transit mixer to afford the benefits aswell as obviate the faults hereinbefore mentioned.

Counting and recording the number of revolutions of each separate mix,being desired, it is another object of the invention to provide meansadapted to be re-set to zero so that such separate counting may beeffected.

A further object of the invention is to accumulate the different countsof the revolutions of the mixer drum, thereby providing a means todetermine service requirements of the mixer appartus and useful lifeexpectancy.

The invention also has for its objects to provide such means that arepositive in operation, convenient in use, easily installed in a workingposition and easily disconnected therefrom, economical of manufacture,relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novelcombinations and arrangements of parts, which will more fully appear inthe course of the following description. However, the drawing merelyshows and the following description merely describes, one embodiment ofthe present invention, which is given by way of illustration or exampleonly.

In the drawing, like reference characters designate similar parts in theseveral views.

Fig. 1 is a top plan view of a generally conventional transit type mixerprovided with the present drum-revolution counting means.

Fig. 2 is an enlarged side elevational view of said counting means, thesupport means therefor being shown in cross-section.

Fig. 3 is a face view of the visual indicator of said counting means.

The conventional truck type or transit mixer that is illustrated in Fig.1 is shown as provided with a wheelmounted chassis 5 on the forwardportion of which is "ice provided the usual cab and motive means 6 andthe rearwardportion mounting a mixing drum 7. Said drum is here shown asbeing rotated by an engine or motor 8 provided with a variable speedtransmission 9, through the medium of a speed reducer 10, operativelyconnected to transmission 9 by a drive shaft 11 and a chain. andsprocket drive 12 operatively connecting said reducer 10 and the drum 7.The drum 7 is shown as horizontally disposed, although in practice thesame is at an angle with the open rear end elevated with respect to theopposite end.

The present drum-revolution counting and recording,

means 13 is shown as being driven from the transmission 9. This may bevaried, however, since said means 13 may be driven from the speedreducer 10 or from any part of the means that may be used for rotatingdrum 7.

The means 13 that is illustrated comprises, generally, a driveconnection 14 deriving its rotation from transmission 9 or other meansin the driving train of the drum 7, a tachometer type of unit 15 drivenby connection 14, and a gear box 16 interposed between said connectionand unit to impart a desired speed ratio between the drive of'thetransmission and that of the tachometer.

The drive connection 14 may comprise a flexible shaft 17 enclosed in asheath 18 and extends, in the form shown, from any rotating member intransmission 9 to gear box 16.

Said gear box is provided for the purpose of causing the connection toprovide a proper speed ratio drive to tachometer 15. It will be notedthat the drive between transmission 9 and drum 7 not only goes throughgear box 10 but also includes a chain and sprocket drive 12 that furtherreduces speed. Thus, the speed of shaft 11 is substantially greater thanthe speed of rotation of the drum. Since the tachometer counts drumrevolutions, it is necessary to drive the same at a speed related to thespeed imparted to the drum. Hence, the gear box 16 in the drive to thetachometer.

Said tachometer 15 may follow speedometer design in that the same isprovided with a pointer 19 that sweeps the dial 20 according to theinput speed from gear box 16, and is also provided with an accumulatingcounter 21 and a counter 22 that is re-settable to zero as by a knob 23.By providing said dial with a scale 24 that can be read as drumrevolution speed, visual inspection of the dial will advise of threethings: one, the speed at which the drum 7 is rotating (from zero to 20revolutions per minute); two, the number of revolutions the drum hasmade since the counter 22 had been re-set to zero (241.6

011 the drawing); and, three, the total number of revolutions that thedrum had made during the life of the mixer (28,761 on the drawing).

Thus, the mechanical condition of the mixer, as refiected by use, isshown by counter 21; the number of revolutions of the current mix bycounter 22; and the speed of the mix by pointer 19- and scale 24.Therefore, it is a simple matter to set the drive for the drum to give adesired rotational speed of the drum so that agitation, mixing orcharging may be effected and to determine whether a mix is properlycompleted.

Since the transmission 9 is usually of the reversing type so that drum 7may be reversed when such is desired, the means 25 is provided forde-clutching the tachometer from gear box 16 during such reversal.Instead of such a control, a slip clutch may be interposed between thegear box and the tachometer.

While the foregoing has illustrated and described what is nowcontemplated to be the best mode of carrying out the invention, theconstruction is, of course, subject to modification without departingfrom the spirit and scope of the invention. It is, therefore, notdesired to restrict the invention to the particular form of constructionillustrated and described, but to cover all modifications that may fallwithin the scope of the appended claims.

Having thus described the invention, what is claimed and desired to'besecured by Letters Patent is:

1. In combination with a truck-mounted cement mixer having a rotatingdrum and a drive means for said drum, atachometer to count revolutionsand show speed of revolutions of the drum, drive means interconnectingthe tachometer and the drum, and a slip clutch interposed in the drivemeans for the tachometer.

2. In combination with a truck-mounted cement mixer having a rotatingdrum and a drive means for said drum, a tachometer to count revolutionsand show speed of revolutions of the drum, drive means interconnectingthe tachometer and the drive means for the drum, a gear box interposedin the drive means for the tachometer to coordinate the operationthereof with the rotation of the drum, and a slip clutch interposedbetween the gear box and the tachometer.

3. In combination with a truck-mounted cement mixer having a rotatingdrum and drive means to rotate said drum first in one direction and thenin a reverse direction, the improvement therewith comprising atachometer to count the number of revolutions of the drum in onedirection to thereby measure the texture of the cement mix, drive meansinterconnecting the tachometer and the drum, and a slip clutchinterposed in the drive means for the tachometer, said clutchdisconnecting said drive means from the tachometer when the drum isrotated in a reverse direction.

References Cited in the file of this patent UNITED STATES PATENTS1,148,125 Stewart July 27, 1915 1,182,022 Larson May 9, 1916 Berge Nov.2, 1926

